This invention relates to the field of labeling, and, more particularly, to a labeling apparatus and associated method, such as for the application of labels to fruit and/or vegetables.
Labels are applied to fruit and vegetables in packing houses, where the speed at which the labels are applied, the accuracy of the label application, and the space required by the labeler, i.e. the labeler footprint, are important. Speed is important because the fruit must be packed and shipped quickly so that the shelf life in stores will be as long as possible and the speed of the labeler may be a limiting constraint. This constraint of labeler speed may also result in inefficient use of other equipment and personnel in the packing house, thus increasing the overall cost of operation.
Accuracy, in the form of the successful application of the proper label to the fruit, is important because packing house profitability is adversely affected when a label that would have permitted a higher selling price is not applied to fruit otherwise capable of commanding such a higher price. Space is also important because of the physical configuration of any given packing house. The fruit is transported in a series of lanes, each lane conveying fruit on a plurality of cradles connected to an endless belt, each cradle supporting and locating an individual fruit. The fruit in each lane is sized by conventional sizing equipment and subsequently conveyed past a plurality of labelers arranged in series or banks, each of the labelers in the series of labelers being loaded with a different label, i.e. a label imprinted with indicia to identify the size of the fruit. The physical arrangement of the packing house often limits, without major reconstruction of the building, the number of banks of labelers it is possible to install.
U.S. Pat. No. 4,547,252 to LaMers discloses a labeling apparatus, such as for fruit, and including an extendable bellows for placing the labels. The bellows is moved past a magazine or cassette which dispenses the labels from a carrier strip. The labels are held in position on the distal end of the bellows by application of a vacuum to the bellows, which also serves to maintain the bellows in a retracted position. As the bellows is moved to an application position adjacent a fruit, positive pressure is applied and the bellows is extended to contact the fruit and apply the label thereto.
As also disclosed in the patent, a tricuspid check valve is integrally formed on the distal end of the bellows. The valve admits air from outside the bellows to the interior of the bellows, but prevents the flow of air out of the bellows. Accordingly, in theory, the label may be held in position by the vacuum applied to maintain the bellows in the retracted position. When the bellows is extended by positive air pressure, the valve in theory is closed to prevent blowing the label off of the end of the bellows and thereby missing the fruit.
Unfortunately, the integrally formed check valve may become gummed with adhesive from the adhesive labels or from wax carried by the fruit. If the valve becomes stuck open, when positive pressure is applied, the label may be ejected prematurely. If the valve becomes gummed in a closed position, the bellows may not pick up the labels and the dispensing cassette may jam thereby requiring maintenance.
Published European patent application 113,256 assigned to Sinclair discloses a labeler including a plurality of extendable bellows rotated between label pick-up and label applying positions. In a related commercial embodiment of the Sinclair labeler, a flexible diaphragm has been used in place of the tricuspid check valve. The flexible diaphragm is secured to the inside distal end of the bellows. When a vacuum is applied, the diaphragm opens to expose a series of openings in the distal end. Accordingly, the label is held in position by vacuum communicated to the end openings. When positive pressure is applied to extend the bellows, the flexible diaphragm desirably seals against the openings.
Unfortunately, the diaphragm arrangement may be subject to the same shortcomings as the tricuspid check valve. In other words, the accumulation of adhesive and/or wax could stick the diaphragm in either the opened or closed positions. Accordingly, fruit may not be properly labeled, and additional maintenance may be required for the labeler.
U.S. Pat. No. 3,450,590 to LaMers discloses a labeler including a reciprocating bellows movable between retracted and extended positions for applying labels to passing objects. A central pipe extends through the interior of the bellows. A very slight vacuum is applied to the pipe to just hold the label to the opening of the pipe at the end of the bellows. Unfortunately, the central pipe may interfere with the reciprocating movement of the bellows. In addition, the slight vacuum applied by the pipe may be insufficient to retain the label, especially if the adhesive clogs a portion of the end of the pipe. The constant supply of vacuum may also result in the accumulation of adhesive and debris on the end and into the interior of the pipe.
In view of the foregoing background, it is therefore an object of the present invention to provide a labeling apparatus and associated methods that include one or more bellows that can effectively apply a vacuum to hold a label in position, that properly place the labels on the fruit, and yet which are also resistant to clogging from the label adhesive or fruit wax.
These and other objects, features and advantages in accordance with the present invention are provided by a labeling apparatus comprising at least one bellows being movable between extended and retracted positions responsive to positive and negative internal fluid pressure, respectively, and including a flexible coil tube within the bellows. The bellows preferably includes a cap defining a distal end for carrying the label and has at least one cap opening therein. A pleated sidewall may be connected to the cap. The flexible coil tube preferably has a distal end connected in fluid communication with the cap openings and a proximal end for being connected to negative and positive fluid pressure, respectively. Accordingly, the label can be retained as desired by applying a vacuum, and debris, such as a stuck label or accumulated adhesive may be cleared from the cap openings.
In one embodiment, a positioner advances the bellows along a path of travel between a label pick-up position and a label application position. A pressure controller selectively connects the bellows and the proximal end of the flexible coil tube to negative and positive fluid pressures as the bellows is advanced along the path of travel.
The pressure controller may include means for, during a first time, connecting the bellows to positive fluid pressure while connecting the proximal end of the flexible coil tube to negative pressure to retain the label as the bellows is moved to the extended position. The controller may also include means for, during a second time period after the first time period, connecting the proximal end of the flexible coil tube to positive fluid pressure while connecting the bellows to negative fluid pressure. This will serve to expel debris or a label not applied to an article as the bellows is moved to the retracted position. Accordingly, the flexible coil tube may be used to apply vacuum to hold the label against the end of the bellows, and to apply positive pressure to clear the cap openings, such as to expel a stuck label.
The labeling apparatus may further comprise a rotatable frame, and a plurality of bellows may be mounted on the rotatable frame. In this embodiment, the positioner rotates the rotatable frame to position the plurality of bellows.
Considered in somewhat different terms, the labeler in some embodiments may include a fluid pressure manifold defining at least one negative pressure port and at least one positive pressure port therein. The rotatable frame surrounds the fluid pressure manifold and has a series of spaced apart first and second openings therein. The bellows are carried by the rotatable frame so that each bellows is connected to a corresponding first opening in the rotatable frame. Accordingly, as the rotatable frame rotates in registry with the respective manifold ports, the bellows is movable between extended and retracted positions responsive to coupling to positive and negative fluid pressure, respectively.
The respective flexible coil tube positioned within each bellows has a distal end connected in fluid communication with the cap openings and a proximal end connected separately from the bellows to a corresponding second opening in the rotatable frame. Thus, rotation of the rotatable frame about the fluid pressure manifold advances each of the bellows along a path of travel between a label pick-up position and a label application position, and selectively aligns the respective pressure ports with the second openings in the rotatable frame so that each flexible coil tube is connected to negative pressure at at least the label pick-up position.
Coils of the flexible coil tube preferably define a longitudinal axis extending along a direction of extension and retraction of the bellows. The flexible coil tube also preferably includes a material having a shape memory so that the flexible coil tube biases the at least one bellows toward the retracted position. Coils of the flexible coil are preferably positioned within a rigid mounting cup when the bellows is in the retracted position.
A partition member may be positioned in an interior portion of the bellows adjacent the distal end thereof to define a distal end chamber in fluid communication with the cap openings. The distal end of the flexible coil tube may be connected in fluid communication with the distal end chamber. In addition, stop means may be provided within the distal end chamber for defining a first positive stop between the partition member and the cap. A second positive stop may be provided by outermost portions of the rigid mounting cup contacting the partition member when the bellows is in the retracted position.
One method aspect of the invention is for making a label applying apparatus comprising at least one bellows movable between extended and retracted positions responsive to positive and negative fluid pressure. The at least one bellows preferably comprises a cap defining a distal end for carrying the label and having at least one cap opening therein, and a pleated sidewall connected to the cap. The method preferably comprises the steps of forming a flexible coil tube, positioning the flexible coil tube within the at least one bellows, and connecting a proximal end of the flexible coil tube in fluid communication with the at least one cap opening.